1. Field of the Invention
The present invention relates to a laser beam machine, and more particularly to a laser beam machine that can monitor a processing situation of the workpiece.
2. Description of the Related Art
A conventional laser beam processing apparatus has been well known, which comprises a laser oscillator for producing a laser beam, a focus head for directing the laser beam from this laser oscillator onto a processing object, photo detecting means for detecting a light emanating from a portion of the processing object fused by irradiation with the laser beam, and a control unit for controlling the laser oscillator while monitoring a processing situation of the workpiece based on the quantity of light detected by the photo detecting means (e.g., refer to JP-A-4-81286, page 2, FIG. 1). Also, the above laser beam processing apparatus may be provided with reference light generating means and a detection function determining portion, so that the photo detecting means is determined as defective if the detected quantity of light is smaller than a preset quantity of light (e.g., refer to JP-A-2705485, page 1, FIG. 1).